1. Field of the Invention
This invention relates to a method for disposing of waste fluids containing organic wastes and, more particularly, relates to a method for preventing escape of organic waste material from a waste disposal site.
2. Prior Art
One of the major problems facing cities, chemical manufacturers, and industries using various chemicals is waste disposal. More particularly, cities and industries are often faced with the disposal of mixtures and/or emulsions of organic contaminants. Typically, these are aqueous compositions, however, there exists waste fluids which are compositions of organic contaminants and polar fluids. In many of these operations, the disposal of water containing the contaminant substances is a problem. Regulations make it impossible to simply dump such waste water into streams, even if such method of disposal were desirable. Various methods have been proposed for removing such contaminants from waste water, but they have been relatively expensive or inefficient. Theerefore, the removal of the contaminants from aqueous solutions, and in particular from waste water containing small amounts, is a problem which has not been completely solved.
One method in common use for organic waste disposal, utilizes waste disposal sites. Current such methods generally call for burying organic-containing waste in a lined area of containment to attempt to physically isolate the waste from any surface or ground water near the disposal site. These methods often include the use of polymer liners, bentonite liners, and bentonite-polymer liners (e.g. Vol clay) for the site. These techniques, however, suffer from two major problems. First, it is extremely difficult, if not impossible, to engineer a waste disposal site without having leaks occur in the engineered barriers either during initial implacement, or with time as the engineered barriers age. In the case of polymer liners, the problem of initial implacement is a major drawback since it is difficult to manufacture large sheets of synthetic liners that have no leaks, and because the sheets have finite sizes and must be sealed in the field. This sealing operation is very difficult to accomplish without leaks. One additional problem is that the presently used synthetic liners are also susceptible to puncture. A further major problem with polymers, is that after a finite period, sometimes within five to ten years, the polymer may begin to degrade badly, and to crack and rupture.
The bentonite and betonite-polymer mixtures overcome some of the problems associated with polymeric liners. A problem with the clay liners is that in order to form the water impermeable layer, the swelling properties of the bentonite are of special significance. These properties, unfortunately, are a strong function of ground-water salinity and of wetting and drying cycles. Leaks in bentonite liners can be caused by ground water composition in at least two ways. If the salinity of the ground water or leachate is high, the swelling properties of the clay may be drastically altered. Secondly, if the ground water or leachate has a high content of divalent metals such as calcium or magnesium, again the swelling properties and thus the permeability of the clay may be drastically altered. Leaks can also occur through repeated cycles of wetting and drying that allow cracks to form in the liner. This will be the case in most landfills where the site is located in the unsaturated soil zone.
Bentonite clay liners have also been shown to be very sensitive to some organics. It has been shown that bentonite liners undergo dehydration reactions when exposed to organics such as acetone that result in cracking of the liner.
A second major problem with all of these approaches is that they incorporate site designs that act like bathtubs. This may require some remedial action at some point to drain and treat the leachate that accumulates to ensure that leachate does not escape as overflow or breakthrough.
The following prior art is relevant to this invention:
U.S. Pat. No. 2,367,384 to Tymstra; PA1 U.S. Pat. No. 2,937,142 to Rios; PA1 U.S. Pat. No. 3,487,928 to Canevari; PA1 U.S. Pat. No. 3,938,770 to Goodrich et al; PA1 U.S. Pat. No. 4,033,764 to Colegate et al; PA1 U.S. Pat. No. 4,231,866 to Moser et al; PA1 U.S. Pat. No. 4,279,756 to Weiss et al; PA1 U.S. Pat. No. 9,149,968 to Kupiec; PA1 British Pat. No. 1,280,373 to Davies et al; and PA1 Japanese patent application No. 015979 to Koyo Kasei KK. PA1 U.S. Pat. No. 2,531,427 to Hauser; PA1 U.S. Pat. No. 2,966,506 to Jordan; PA1 U.S. Pat. No. 3,422,185 to Kuritzkef; PA1 U.S. Pat. No. 3,974,125 to Oswald; PA1 U.S. Pat. No. 4,081,496 to Finlayson; and PA1 U.S. Pat. No. 4,105,578 to Finlayson et al.
More specifically, Tymstra describes a method for removing small quantities of water-imiscible organic oily impurities from water. The method consists of contacting the oily composition with an inert solid coated with a cation surface-active bonding agent. The solid employed may be beach sand, mud flat deposits, silt, clay, limestone, silica, rice hulls, etc. The cationic surface-active bonding agent may be quaternary ammonium, phosphonium, arsonium, or primary, secondary, or tertiary organic organic amines or saltss thereof.
Rios separates phenolic substances from aqueous solutions by contacting the aqueous solution with a clay absorbent. The clay is previously treated by depositing carbonaceous material thereon, and then subjecting it to combustion regeneration to burn off the carbonaceous material.
Canevari separates droplets of oil from an aqueous phase, using a mixture comprising a sodium montmorillonite clay and an organic cationic agent or glycol. The organic cationic agent is preferably an amine. The mixture is applied as a flocculating clarifying solution containing from 1 to 5% of clay to water, and an effective amount of the organic cationic agent or glycol.
Goodrich et al describes the use of an anionic polyelectrolyte and a sodium or a calcium montmorillonite clay to effectively separate water oil droplets in sea water.
Colegate et al describes scavenging metal ions from solution by means of a complexing agent comprised of an inorganic substrate, such as a clay mineral, with covalent organic molecules, such as onium compounds, chemically bonded to the substrate.
Kupiec describes the use of bentonite clays and portland cement in aqueous solutions containing polluting materials, e.g. metallic ions, to form a solid mass.
Moser et al separates organic and aqueous phases by treatment of the emulsions with diatomaceous earth at an elevated temperature.
Weiss et al describes the use of a finely divide particulate mineral or clay material, the individual particles of which have been treated to produce a thin hydroxylated surface layer having a positive zeta potential at the adsorption pH.
Davies et al describes the separation of an oil from an emulsion. Several methods are enumerated for forming the emulsion into two layers for evaporation of the aqueous layer. One of these methods utilizes a mixture of surface-active clay and a polyelectrolyte is added to the emulsion. Bentonite is described as particularly suitable polyelectrolytes.
Koyo Kasei KK describes the detoxification of PCB-containing waste water by mixing the waste water with diatomaceous earth, bentonite or other clay which has been made lipophilic, and then mixing with cement, water, and aggregate. In the method less than 20% PCB waster liquor, sludges, etc., are mixed with the diatomaceous earth, bentonite, or clay minerals of inorganic fine particles previously made lipophilic by surface treatment. The PCB's are allowed to be absorbed on the mineral, and then the resulting materials are mixed with cement, water, and aggregate. Diffusing or leaching appears to be reduced. Activated carbons or silica gel may also be used in place of the clay.
Additionally, organoclays are well-known in the art, see for example the following U.S. patents:
None of these aforementioned references teach or suggest the use of these organoclays to prevent the escape of organic waste material from a waste site.